The error message is pointing on a missing inbound rule "allow RDP TCP Port 3389".
You need to create this inbound rule in the associated Network Security Group (NSG).
Microsoft Certification / Exams is currently not supported in the Q&A forums.
Maybe one of the links is helpful:
https://trainingsupport.microsoft.com/en-us?auth=1
https://techcommunity.microsoft.com/t5/microsoft-learn/ct-p/MicrosoftLearn
https://trainingsupport.microsoft.com/en-us/mcp/forum?sort=LastReplyDate&dir=Desc&tab=All&status=all&mod=&modAge=&advFil=&postedAfter=&postedBefore=&threadType=all&isFilterExpanded=false&page=1
(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)
Regards
Andreas Baumgarten